efriedma created this revision.
efriedma added reviewers: EricWF, compnerd.
This is basically part 2 of r313694.
It's a little unfortunate that I had to copy-paste atomic_support.h, but I
don't really see any alternative.
The refstring.h changes are the same as the libcxx changes in r313694.
Repository:
rCXXA libc++abi
https://reviews.llvm.org/D45196
Files:
src/cxa_default_handlers.cpp
src/cxa_exception.cpp
src/cxa_handlers.cpp
src/include/atomic_support.h
src/include/refstring.h
Index: src/include/refstring.h
===
--- src/include/refstring.h
+++ src/include/refstring.h
@@ -22,6 +22,7 @@
#include
#include
#endif
+#include "atomic_support.h"
_LIBCPP_BEGIN_NAMESPACE_STD
@@ -87,19 +88,19 @@
: __imp_(s.__imp_)
{
if (__uses_refcount())
-__sync_add_and_fetch(&rep_from_data(__imp_)->count, 1);
+__libcpp_atomic_add(&rep_from_data(__imp_)->count, 1);
}
inline
__libcpp_refstring& __libcpp_refstring::operator=(__libcpp_refstring const& s) _NOEXCEPT {
bool adjust_old_count = __uses_refcount();
struct _Rep_base *old_rep = rep_from_data(__imp_);
__imp_ = s.__imp_;
if (__uses_refcount())
-__sync_add_and_fetch(&rep_from_data(__imp_)->count, 1);
+__libcpp_atomic_add(&rep_from_data(__imp_)->count, 1);
if (adjust_old_count)
{
-if (__sync_add_and_fetch(&old_rep->count, count_t(-1)) < 0)
+if (__libcpp_atomic_add(&old_rep->count, count_t(-1)) < 0)
{
::operator delete(old_rep);
}
@@ -111,7 +112,7 @@
__libcpp_refstring::~__libcpp_refstring() {
if (__uses_refcount()) {
_Rep_base* rep = rep_from_data(__imp_);
-if (__sync_add_and_fetch(&rep->count, count_t(-1)) < 0) {
+if (__libcpp_atomic_add(&rep->count, count_t(-1)) < 0) {
::operator delete(rep);
}
}
Index: src/include/atomic_support.h
===
--- /dev/null
+++ src/include/atomic_support.h
@@ -0,0 +1,181 @@
+//===--===
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===--===
+
+// FIXME: This file is copied from libcxx/src/include/atomic_support.h. Instead
+// of duplicating the file in libc++abi we should require that the libc++
+// sources are available when building libc++abi.
+
+#ifndef ATOMIC_SUPPORT_H
+#define ATOMIC_SUPPORT_H
+
+#include "__config"
+#include "memory" // for __libcpp_relaxed_load
+
+#if defined(__clang__) && __has_builtin(__atomic_load_n) \
+ && __has_builtin(__atomic_store_n)\
+ && __has_builtin(__atomic_add_fetch) \
+ && __has_builtin(__atomic_exchange_n) \
+ && __has_builtin(__atomic_compare_exchange_n) \
+ && defined(__ATOMIC_RELAXED) \
+ && defined(__ATOMIC_CONSUME) \
+ && defined(__ATOMIC_ACQUIRE) \
+ && defined(__ATOMIC_RELEASE) \
+ && defined(__ATOMIC_ACQ_REL) \
+ && defined(__ATOMIC_SEQ_CST)
+# define _LIBCXXABI_HAS_ATOMIC_BUILTINS
+#elif !defined(__clang__) && defined(_GNUC_VER) && _GNUC_VER >= 407
+# define _LIBCXXABI_HAS_ATOMIC_BUILTINS
+#endif
+
+#if !defined(_LIBCXXABI_HAS_ATOMIC_BUILTINS) && !defined(_LIBCXXABI_HAS_NO_THREADS)
+# if defined(_LIBCPP_WARNING)
+_LIBCPP_WARNING("Building libc++ without __atomic builtins is unsupported")
+# else
+# warning Building libc++ without __atomic builtins is unsupported
+# endif
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+namespace {
+
+#if defined(_LIBCXXABI_HAS_ATOMIC_BUILTINS) && !defined(_LIBCXXABI_HAS_NO_THREADS)
+
+enum __libcpp_atomic_order {
+_AO_Relaxed = __ATOMIC_RELAXED,
+_AO_Consume = __ATOMIC_CONSUME,
+_AO_Acquire = __ATOMIC_ACQUIRE,
+_AO_Release = __ATOMIC_RELEASE,
+_AO_Acq_Rel = __ATOMIC_ACQ_REL,
+_AO_Seq = __ATOMIC_SEQ_CST
+};
+
+template
+inline _LIBCPP_INLINE_VISIBILITY
+void __libcpp_atomic_store(_ValueType* __dest, _FromType __val,
+ int __order = _AO_Seq)
+{
+__atomic_store_n(__dest, __val, __order);
+}
+
+template
+inline _LIBCPP_INLINE_VISIBILITY
+void __libcpp_relaxed_store(_ValueType* __dest, _FromType __val)
+{
+__atomic_store_n(__dest, __val, _AO_Relaxed);
+}
+
+template
+inline _LIBCPP_INLINE_VISIBILITY
+_ValueType __libcpp_atomic_load(_ValueType const* __val,
+int __order = _AO_Seq)
+{
+return __atomic_load_
